Double objective.



N0. 873,896- PATENTED DEC. 17, 1907. M- VON ROHR.

DOUBLE OBJECTIVE. APPLICATION FILED xunnas,1aom

t I THE NORRIS PETERS m. WASHINGTON. P- C- t To all whom it may concern:

UNITED STATES PATENT OFFICE.

MORITZ VON ROHR, OF JENA, GERMANY, ASSIGNOR TO THE FIRM OF CARL ZEISS, OF J'ENA, GERMANY.

DOUBLE OBJECTIVE.

Specification of Letters Patent.

Patented Dec. 17, 1907.

Be it known that I, MoRrTz VON RoHR, doctor of philosophy, a citizen of the German Empire, and residing at Carl Zeiss strasse, Jena, in the Grand Duchy of Saxe-Weimar, Germany, have invented a new and useful Double Objective, of which the following is a specification.

The double objective accordin to the present invention is corrected sp erically, chromatically and for coma for a very large relative aperture, because it is designed to serve as a micro-projection system or more articularly as a powerful ma nifier having a large field of view. It resem les in its con stitution a well-known design of a photographic double objective, of whose two identical and symmetrically arranged components each one consists of two lenses-an inner lano-concave flint glass lens with the plane surface placed innermost and an outer '-convex crown glass lensand presents a dispersive pair of facing surfaces the curvatures of which are unequal. The adaptation of such asymmetrical objective for the purposes mentioned above has proved to be impossible. Because of the very lar e relative aperture the correction of coma reIatively to distant image points can only be effected, when the symmetrical arrangement of the lenses is abandoned, the component from which the pencils emerge in parallel rays is given a pair of facing surfaces of less power than the other, and in the same component the non-concave surface of the flint glass lens is made of less curvature than in the other component.

In the drawing the new double objective is represented as a magnifier having a magnifying power of nine. The constructional data 40 respecting this magnifier are com iled 1n the following tables. The radii, thic esses and distances have reference. to a focal length I claim:

A spherically and chromatically corrected double objective, the components of which consist each of two lenses including a dispersive pair of facing surfaces the curvatures of which are unequal, the inner one of both lenses being made of flint glass and turning a non-concave surface towards the other component, and the component from which the pencils emerge in parallel rays presenti a pair of facing surfaces of less power an a non-concave surface of less curv-' ature.

MORITZ VON ROHR.

Witnesses PAUL KRiieER, FRITZ SANDER. 

